these judgments with the precision necessary to quantify them, we left this program out of the analysis. While some fraction of currently cohabiting taxpayers might pay a marriage penalty if they were to marry, the overall poverty-reducing effects of marriage are likely to move many more families off the EITC rolls. (See appendix A for more detail.)

Similarly, some fraction of public school budgets is likely spent in dealing with social problems created by divorce and unmarried childbearing. Children whose parents stay married are less likely to repeat a grade, exhibit conduct disorders requiring special education outlays, or require expensive special education services generally. Again, none of these costs are reflected in our analysis.

We have also excluded one of the largest taxpayer costs on the book: Medicaid for the elderly and Medicare for unmarried adults. They are excluded partly because most people do not think of older single adults when they think of “fragmented families.” But high rates of divorce and failure to marry mean that many more Americans enter late middle-age (and beyond) without a spouse to help them man- age chronic illnesses, or to help care for them if they become disabled.43 Through the Medicare and Medicaid system taxpayers are picking up a large, but difficult to quantify, part of the costs as a result.

Third, we have ignored for the purposes of this analysis any behavioral effects of marriage. We have assumed that all the benefits of marriage come solely from reduced rates of poverty for children, ignoring the evidence that stably married par- ents provide human and social capital to their children other than income in ways that increase children’s well-being and reduce the likelihood they will need or incur expensive government services, from repeating grades at school to ending up in the child protective system or the juvenile justice system.

Similarly, we have assumed no behavioral effects of marriage on fathers’ earning capacity. If stable marriage increases men’s earnings, as the literature suggests, and/or decreases the likelihood that they will commit crimes as adults, our methodology most likely underestimates the taxpayer costs associated with unmarried parenthood.

Fourth, there is one other major reason we believe $112 billion each year repre- sents a cautious, minimum estimate: For the purposes of this analysis, we assume that households that marry will “take up” or use government benefits for which they are eligible at the same rate as single-mother households. In reality, existing data shows that lower-income married couples are far less likely to choose to use gov- ernment benefits for which they are eligible than single-mother households. Overall, single mothers are roughly twice as likely to take advantage of government benefits for which they are eligible than are low-income married couples.44